Authorities spent months investigating a Long Island home health aide accused of stealing from an old man, but busted her only after she won a $5 million lottery prize, her lawyer charged yesterday.

The lawyer spoke out as the Nassau County District Attorney’s Office said investigators were continuing to probe Lydia Moore to see if she had fleeced other elderly people formerly in her care.

Moore, 54, a grandmother, was arrested Friday for allegedly filching $113,000 from the bank account of an 87- year-old Nassau County man before she struck it rich by winning $5 million in the Livin’ Large scratch-off lottery a week ago.

“They had quite some time to bring these charges, but I think the evidence was just weak,” claimed Moore’s lawyer, James Toner.

“I think it’s a little strange to have this evidence for eight months and then to bring up [charges] right after she wins the lottery.”

Toner said cops were getting nowhere with the investigation into Moore, before smiling pictures of her posing with her enormous check were published.

After her arraignment Friday, Moore, of Glen Cove, paid $25,000 cash bail, and laid low in her Crow Lane home, rejecting the unsolicited offer of spiritual help from a priest who arrived in his Lincoln Navigator.

“When you win the lottery, a lot of people come knocking,” said Toner.

“She’s stoic at this point. I think she’s surprised, but she’s confident of her innocence.”

He said Moore is an office administrator who also worked informally as the elderly man’s home health-care aide seven days a week since being recommended to him in 2000.

The pair were close friends, and Moore did his housekeeping and paid his bills, Toner said.

Authorities began investigating Moore after the man’s niece became suspicious Moore was writing herself checks from his bank accounts, investigators said.

But Toner said the man, who has not been identified, and his niece have been estranged for years.

Nassau police and the district attorney declined to comment on Toner’s claims.